Dr. Donohue: Irritable bowel syndrome never evolves

DR. PAUL DONOHUESyndicated Columnist

Published Friday, August 23, 2002

DEAR DR. DONOHUE: Over time, can irritable bowel syndrome lead to conditions such as ulcerative colitis or diverticulosis? I now have ulcerative colitis and am curious if the recurring diarrhea I have had over the past years could have caused this condition. -- E.L.

ANSWER: At the start, let's clear up any name confusion. "Large intestine," "colon" and "bowel" are different names for the same structure, the 4- to 5-foot tube through which undigested food passes on its way to exit from the body. The colon extracts water from undigested food to keep the body's water reservoirs filled. It is not an inert tube. Wrapped around the colon are muscles that propel food residue in the direction that leads out of the body.

Crampy abdominal pain, bloating and diarrhea often alternating with constipation are three prominent irritable bowel symptoms. Some speculate that the colon muscles listen to the beat of a different drummer. Instead of working in a coordinated fashion, they are out of step. Others feel that patients with the syndrome have a digestive tract that is ultrasensitive to stimuli that a normal digestive tract would not feel.

Ulcerative colitis, on the other hand, is an entirely different process.

Shallow, painful ulcers that bleed and promote diarrhea stud the colon lining. The lining has typical changes that can be seen with a scope or on X-rays. Such changes are not seen in irritable bowel syndrome.

Irritable bowel syndrome does not become ulcerative colitis or diverticulosis or cancer.